I'm trying to understand exactly what the DRM restrictions are on iBookstore purchases. Here's what I understand so far (based only on what I've gleaned from apple.com; I'm at least a few weeks from getting an actual iPad):

- purchases can only be performed with an iPad (or soon, iPhone, iPod Touch) that is connected via wireless, using the iBooks app and an existing iTunes account. Currently you cannot purchase books with the iTunes app itself (either on iPad or on a computer).

- once purchased, iBookstore purchases can be downloaded to any iBooks device that's authorized for the same iTunes account. You can remove books and later get another copy at any time (again, assuming you have wireless connection).

- if you sync to a computer, the books on your iPad are backed up to your iTunes library, and can be moved to another iPad/iPhone that you connect to that computer (assuming its iBooks app is authorized against the same iTunes account).

Despite my best efforts to locate this information on apple.com, I've been unable to determine is how many devices can have simultaneous access to an iBookstore purchase. The iBooks FAQ states that "You can sync your books to any iPads you own." Really? So if I own 100 iPads, I can access 100 copies of the book?

I have an analogous question about App Store purchases. I am guessing the same restriction (whatever it is) applies to both.

As an aside, the fact that you can sync purchases up to your computer seems irrelevant since you can't view it there, and can apparently always get a copy from the cloud using iBooks.

actually the limit afaik is 5 computer systems, and unlimited number of ipods/iphones/ipads synced to each computer. it's always been like that for music, original ipod applications, iphone/touch applications and i imagine the same restriction on books as well. at least i have never heard of any limit on devices synced to a computer. mind, syncing to another computer will remove all previous content.

FWIW I have 1 iTunes account and all the apps I have purchased are sync happily to my iPhone, and several iPod Touchs. As others have said, the limit is by computer, but those computers can support as many iDevices as you wish to throw at them.

The OS4 announcement yesterday said that iBooks on iPhone will sync progress wirelessly so that you can also read on iPad - which implies no limit on how many devices you can put the book on, or at least 2 anyway!

well. i have 1 ipad, 2 iphones and 4 ipods. i'm able to sync the same music between them all. apps sync between the 2 phones and the ipad just fine. there is no mention of limitations in any documentation i've ever read. i guess if you want a hard answer from apple, contact them.

Actually the law states only that engineering the software to strip DRM is illegal. And, promulgating such softwware is also illegal. But actual use of the software on one's own files is not illegal. However, the files are often covered by a Terms of Service agreement (TOS). But a TOS is not a law. In the past various "shrink-wrap" TOS agreements were struck down by the courts. This is NOT legal advice as I am not a lawyer and do not even play one on TV. But it is my understanding of the issue anyway.

if you live in the US, the DMCA states it is illegal to produce, distribute or use software designed to circumvent technical copy-restriction (DRM) methods. this is regardless if they are your "own" files or someone else's. under most TOS you don't "own" the applications or ebooks, you simply license the right to use or read those applications or ebooks.

so if you use the various scripts out there to strip the DRM from .mobi or .epub files that you have in your possession you are breaking the law. fair use rights allow you to back up the copy protected file, not strip the DRM and back that up.

if you live in the US, the DMCA states it is illegal to produce, distribute or use software designed to circumvent technical copy-restriction (DRM) methods. this is regardless if they are your "own" files or someone else's. under most TOS you don't "own" the applications or ebooks, you simply license the right to use or read those applications or ebooks.

so if you use the various scripts out there to strip the DRM from .mobi or .epub files that you have in your possession you are breaking the law. fair use rights allow you to back up the copy protected file, not strip the DRM and back that up.

Fair Use has for a long time allowed you to strip DRM to make software interoperable. That is why the EFF won against Apple on jailbreaking and unlocking. It seems that stripping DRM from legally purchased .epub files bought in iBooks, which are limited to iOS only because of Apple's DRM, would fall under this exception as well. The legality of Fair Use exceptions on DRM removal is entirely dependent on it's intended use. DRM removal is not a black and white, always 100% illegal action. It falls into a grey area somewhere in the middle depending on the circumstances of each case. DMCA laws do not supersede Fair Use.

Hopefully Apple will adopt the same practice of dropping DRM in all their media distribution, as they have done with music. Until then, I won't make the frustrating mistake of buying another iBook again. I'll just purchase elsewhere and import into iBooks.